3.2. Compressibility and volume
The Kawakita and Lüdde model (Eqs. 3 and 4) was used to describe the compressibility behavior of both types of
mixed powders. The constants a and b were determined by plotting data in a P/C versus P graph and linear fitting of
the equation (Table 3). The constant a represents the initial packing, compressibility and porosity, while the constant
b represents the resistance to compaction of the material. The constant a value was high in the case of the normal
fruit powder mixed tablet compared to the effervescent tablet (Table 3). This indicated that the fruit powder mixed
tablet without effervescent agent possessed higher initial porosity and was bulky in nature compared to the powder
containing effervescent agent and more compress able as well. Mixed fruit tablet is more compressible than mixedfruit
tablets containing disintegrants (Ong et al., 2014). Smaller particles of effervescent agent fill up void spaces
between particles which reduces the porosity of powder mix and increase the packing (Podczeck and Sharma,
1996).Thus the value of constant a is higher in case of FPM without effervescent agent than FPM with effervescent
agent.